Combination control and quench valve



P 1941- E. T. DAHL COMBINATION CONTROL AND QUENCH VALVE Filed April 28, 1939 iNVEN'I CIR Envmzm TDflHL Patented Sept. 2, 1941 UNITED STATES PATENT OFFICE comma-non comm. AND QUENCH VALVE Edward '1. Dahl, Abington, Masa, minor to Mason-Neilan Regulator Company,

Boston,

tion and has for an object an improved regulating valve having certain novel features including combined means, first, for providing a substantially balanced single seated valve plug, comparable in this respect to a double seated valve and, second, for introducing an independent fluid which may serve to cool the controlled medium, lubricate the valve parts, or prevent the formation of undesirable deposits.

It is a further object of this invention to provide means for assuring a more complete dispersion of quench liquid by introducing the quench liquid substantially at the center of the valve oriflee, the orifice being preferably of the expanding type, and, as a further aid to atomization, to provide additional means for atomizing the quench liquid at the point of introduction.

In fluid control valves as heretofore constructavoid localized superheat due to flow pockets created by excessive turbulence which are out of the direct path of flow and for that reason do not receive a sufficient quantity of quench liquid.

This is accomplished by providing a valve oriflce having a gradually contracting throat and an expanding outlet and combining this structure with a valve plug adapted to maintain the desired flow characteristics and having means for the introduction of quench liquid into the center of the controlled medium at a point of substantially maximum velocity and where the initial fluid expansion occurs. a

It is a further object of this invention to effect a saving in quench liquid by so arranging and combining the valve orifice, control plug, and quench liquid discharging means, that a central core is formed. in the controlled fluid and the quench liquid is discharged into the central core where it is enveloped in the controlled fluid and dispersed before coming in contact with the colder walls of the fluid conduit.

It is also an object of this invention to provide a non-chattering valve of the single seated bala tendency to break down into various components atexcessive temperature for the pressure andalso having a tendency to form deposits, it will be understood that the valve is applicable for the. control of any type of fluid such as steam or the like.

Having reference to the drawing:

Fig. 1 is a vertical section of a fluid pressure reducing valve embodying my invention.

Fig. 2 is an enlarged vertical section of the lower portion of the valve shown in Fig. 1.

Fig. 3 is a similar view with the parts in a different position.

Fig. 4 is a bottom plan view of the valve plug. Fig. 5 is a diagram illustrating the flow of controlled fluid and the dispersion of quench liquid therein.

Having reference to the drawing, a reducing valve I0 is shown which is preferably of the general type illustrated and described in my co-pendingappllcation, Serial No. 189,950flled Feb. 11, 1938, comprising a body ll having an angular inlet passage l2 and an expanding discharge passage l3, said passages being connected to inlet and discharge Pipes l4 and I5 by means of suitable flanges l6 and I1, as by bolts l8. Communication from the inlet passage to the outlet passage is effected through an oriflce l9 included in a nozzle member 20 having a restricted throat 2| and an expanded outlet 22, same being arranged to gradually increase the velocity of fluid flow to the orifice and thereafter to gradually diminish the velocity as the fluid discharges to the valve outlet.

The inlet passage i2 is preferably enlarged at 23 to accommodate for the displacement of a cylindrical valve plug 24 one end of which is guidmm a liner 25 secured in the valve body II and the other end of which has a seating portion 26 adapted to cooperate with a corresponding seating portion 21 around the orifice in the nozzle member. Secured to the valve body II by bolts 28 is a recessed flange 29, herein shown as integral with an intermediate 30 having cooling fins 3|. The liner 25, upper end of the plug 24, and the recessed flange 29 together form a chamber 32 which, as will be hereinafter described, may be conveniently termed a combined pressure balancing and quench liquid supply chamber.

Suitable means for operating the valve plug 24 may include a diaphragm 33 mounted in a diaphragm chamber 34 subjected to operating fluid pressure through a connection 35 and pipe 36 from a'suitable source of supply and govemed by a condition responsive device such as an air operated instrument or the like, not shown. The diaphragm 33 may be connected to the plug 24 by a stem 31 which extends through a guide opening in the intermediate 30 and is surrounded by a compression spring 38 mounted between and a suitable button 40 connected to one end of the stem and adapted to engage the diaphragm I The other end of the stem 31- extends 33. a through a guide bushing 4| threaded" intoa recess 42 formed in the upper end of the plug, and secured to the stem is a collar 42 adapted to engage the lower surface of the guide bushing;

an adjustable member ion the intermediate and to lift the plug 24 off its seat when the l is raised by the spring. as occurs ona decrease derstood that any other suitable power device-or hand operating means may be employed.

The combined pressure balancing. and supply chamber 32 is in fluid communication with the inlet passage I2 by means of the restricted passage 44 between the valve plug 24 and the liner 25, and for this purpose I preferably allow a clearance of between .005 inch and .020 inch. The passage 44 also affords means for introducing liquid for lubricating the plug and liner when the valve is open, and for preventing the formation of deposits around the plug and seat and in the valve body when the valve is closed. Suitable liquid for this purpose may be supplied to the passage from a fluid flush line 45 which connects with an annular space 40 around the lower end of the liner, said space being in communication with the passage by a plurality of ports 41.

A combination cooling and quenching liquid may be supplied to the chamber by means of a pipe 48 connected to a lateral port 40 in the intennediate 30 through which it communicates with a passage 50 formed in the intermediate around the valve stem 31 which passage extends from the port 49 to the chamber 22. The supply passage 50 is designed to pass a sufficient quantity of liquid for cooling the stem 31 under conditions of high temperature, and also for desuperheating purposes. in a manner to be disclosed.

Means for introducing a controlled supply of quenching liquid from the chamber 32 to the outlet passage l3 and for providing controlled pressure communication between said outlet passage and chamber will now be described. The valve plug 24 is provided with a central longitudinal conduit extending from the recess 42 below the guide bushing 4| to the lower end of the plug where it terminates substantially at the restricted portion of the orifice l9 and centrally thereof. As herein shown this passage is of larger capacity than the supply passage 50 referred to above. The lower end of the plug is preferably of parabolic shape, as indicated at 52, and is designed both to cooperate with the orifice l9 to efiect the flow characteristics desired and also to form a central core in the controlled fluid by means of an abruptly terminating end portion 52 within which the quench liquid conduit 5i discharges. The arrangement of parts is such that the conduit is adapted to discharge into the central core of controlled fluid at a point of substantially maximum velocity an'd where the initial fluid expansion occurs.

The upper end of the central conduit Si is controlled by a pilot valve member 83 formed on the end of the stem 31 and adapted to cotime with the conduit to control therflow offluid between the chamber 22*andthe valve outlet passage It. The parts 'are so arranged that when the collar. 42 engages the guide bushing. 4! the pilot valve is open and permits {fluid :communication between the chamber 22 and the discharge-9J3 by means ofports .54 10- catedin theupper end of the plug, and whenj the" valve plug .24 isgseated andthe pilot yalve' member 352 engages :the plug a" positive closing pressure is exertedon-theiyalveplng and the conduit u is closed.'.. while menot-vaive; 195*. closed the upstream pre 1; .mm'mummted to the chamber 22 by meansoLtherestricted passage 44 and-provides pressure 01! balance further tending to seat the plug 24. When the pilot is open the oil! balance is substantially eliminated, as the capacity of the conduit is greater than that of the supply passage Ill, and at the same time quench liquid is introduced for desuperheating the controlled fluid. Thus the chamber 22 functions as a means for determining the condition of balance or oif balance of the plug and as a means for supplying quench liquid to the controlled fluid, both functions being governed by the pilot valve.

As a further aid to atomization of the quench liquid I provide lateral ports in the lower end of the valve plug 24 beneath its seat 28 which preferably incline downwardly toward th central passage ii and terminate at the periphery thereof. The ports 55 are located adjacent to the seat 26 in a comparatively straight section 56 having cylindrical walls substantially parallel with the axis of the orifice and making a reasonably close fit with said orifice. The .parts are so arranged that the cross-sectional area of the straight section II is preferably not less than 6 to 8 per cent in excess of the area of that portion of the valve plug 24 extending into the liner 25. This affords a slight off balance tending to urge the plug towards its seat and eliminates chattering due to the high velocity of fluid flow which would otherwise occur because of the provision for relative movement of the pilot valve 53 and plug 24. While a spring may be used for urging the pilot valve towards open position to prevent chattering I prefer the construction Just described. I have found that it is usually necessary to provide a seating area 26 substantially 10 per cent greater than the area 24 and therefore when the valve is closed the area having a tendency to urge the valve towards its seat is substantially 10 per cent greater than when the i valve is open. For this reason the valve tends to Jump slightly when first lifted off its seat and the straight section 56 is extended below the ports to prevent any substantial controlled fluid flow around the valve plug caused by this action.

In operation, when the main valve plug 24 and pilot valve member 53 are seated the flow oi quench liquid from the supply chamber 32 to the conduit 5! is shut off and the upstream pressure builds up in the chamber 32 through the passage 44 afiording additional pressure for closing the main valve. When the stem is raised the pilot member 53 opens, substantially equalizing the pressure in the chamber 32 with that on the downstream side of the valve, and at the same time admitting the quench liquid into the central conduit. The main valve plug is then raised from its seat by the stem due to the engagement oi the collar 43 with the guide bushing 4|, and the atomizing ports 55 conduct a portion of the controlled fluid into the central conduit imparting a spinning motion to the quench liquid as shown diagrammatically in Fig. 5, and the main flow of control fluid passes around the end of the plug forming a core which envelops the atomized liquid and causes it to be completely dispersed.

Under some conditions it may be beneficial to introduce the quench liquid at a pressure which is about two pounds less than the pressure in the discharge passage ii for I find that an aspirating effect is produced which will overcome the two-pound differential and will cause the quench liquid to flow to the discharge passage.

Under these conditions a check valve 51 should be used in the supply line 48 to prevent a return of quench liquid through the supply line when the control valve is closed. It may also be desirable under certain conditions to introduce liquid through the connection 45 in order to prevent the formation of deposits in the inlet passage i2 when the valve is closed and to lubricate the valve plug when the valve is open. Under these conditions the liquid may be supplied at a pressure somewhat higher than the valve inlet pressure without interfering with the introduction of quench liquid through the flush connection 49 at a considerably lower pressure because the appended claims.

Having thus described my invention, I claim: 1. In a pressure fluid control valve having inlet and outlet passages with a control orifice therebetween, the combination with a valve plug movable relatively to said orifice for governing the flow of fluid through said valve and means for operating said plug, of a conduit for directing a stream of quench liquid into said orifice, at a point apart from its walls, in the direction of controlled fluid flow and substantially parallel to the orifice axis, and means for supplying quench liquid to said conduit.

2. In a fluid pressure control valve having inlet and outlet passages with a control orifice therebetween the combination with a valve plug movable relatively to said orifice for governing the flow of fluid through said valve and means for operating said plug, of a conduit for directing a stream of quench liquid into said orifice substantially at the axis thereof and in a direction substantially parallel to said axis, and means for supplying quench liquid through said conduit.

3. In a fluid pressure control valve having inlet and outlet passages with a control orifice therebetween the combination with a valve plug movable relatively to said orifice for governing the flow of fluid through said valve and means for operating said plug, of a conduit in said valve plug for directing a flow of quench liquid into said orifice in the direction of controlled fluid flow and substantially parallel with the orifice axis, and means for supplying quench liquid to said conduit.

4. In a fluid pressure control valve having inlet and outlet passages with a control orifice therebetween, the combination with a valve plug movable axially to said orifice for governing the flow of fluid through said valve and means for operating said plug, of a conduit in said valve plug fordirecting a stream of quench liquid into said orifice in the direction of controlled fluid flow and substantially parallel with the orifice axis, and means for supplying quench liquid to said conduit.

5. In a fluid pressure control valve having inlet and outlet passages with a control orifice therebetween the combination with a cylindrical valve plug having an axis coincident with the axis of said orifice for governing the flow of fluid through said valve and means for operating said plug, of a conduit in said valve plug substantially coincident with the axis of said plug, said conduit terminating substantially at the restricted portion ofgsaid orifice, and means for supplying quench liquid to said conduit.

6. In a fluid pressure control valve having an inlet passage and an outlet, the combination with a nozzle including an orifice having an expanding discharge passage communicating from said inlet passage to said outlet, of a valve plug movable relatively to said orifice for governing the flow of fluid through said valve and means for operating said plug, a conduit for directing a stream of quench liquid into said orifice, at a point apart from its walls, in the direction of controlled fluid flow and substantially parallel to the orifice axis, and means for supplying quench liquid to said conduit.

7. In a fluid pressure control valve having an inlet passage and an outlet, the combination with a nozzle including an orifice having a gradually converging throat communicating with said inlet passage and a gradually diverging discharge, of a valve plug movable relatively to said orifice for governing the flow of fluid through said valve, means for operating said plug, a conduit for directing quench liquid into said orifice, at a point apart from its walls, in the direction of controlled fluid flow and substantially parallel to the orifice axis, and means for supplying quench liquid to said conduit.

8. In a fluid pressure control valve having an inlet and an outlet the combination with a nozzle including an orifice and an expanded discharge passage communicating between said inlet and said outlet, of a valve plug movable axially toward and away from said orifice for governing the flow of fluid through said valve, means for operating said plug, a conduit in said valve plug communicating with said orifice substantially at the axis thereof, and means for supplying quench liquid to said conduit.

9. In a fluid pressure control valve having inlet and outlet passages and a control orifice therebetween, the combination with a single seated valve plug cooperating with said orifice and movable relatively thereto for governing the flow of fluid through said valve, of means for operating said plug, a combined liquid supply and fluid pressure chamber in said control valve having a restricted communication with said inwith a single seated valve plug for controlling the flow' of fluid through said valve or a combined pressure balancing and liquid supply chamber having a restricted communication with the inlet side 01' said valve and a free communication with the discharge side of said valve, means for supplying quench liquid to said chamber, a pilot valve for controlling the fiow oi fluid between said supply chamber and said valve discharge, and means for operating said valve plug and said pilot to open said pilot when said plug is moved toward open position and to close said pilot when said plug is closed.

11. In a control valve the combination with a valve plug for controlling the flow. of fluid through said valve, of a conduit for introducing quench liquid directly to the discharge side of said valve. and means associated with said conduit for atomizing quench liquid therein before it discharges from said conduit.

12. In a valve for controlling fluid flow the combination with an orifice of a valve plug having a seating portion cooperating with said orifice to control the fiow oi fluid therethrough, a quench liquid conduit in said valve plug having an opening at the end thereof and communicating with a sourceoi quench liquid supply, a lateral port for communicating fluid pressure externally of said plug to said conduit, said port being located on the discharge side of the seating portion of said plug, and means for moving said plug relatively to the valve orifice to control the flow of fluid through said valve.

13. In a fluid pressure control valve the combination with a control orifice and a valve plug adapted to be reciprocated relatively thereto, of a pressure chamber into which said valve plug extends, a restricted passage from said chamber to the control valve inlet side of said orifice, a fluid conduit from said chamber to the discharge side of said orifice, a pilot valve plug movable relatively to said main valve plug for controlling said conduit and actuating said main valve plug, means for supplying quench liquid to said chamber, and means for operating said pilot valve.

14. In a valve for controlling fluid flow, the combination with an orlfice,.ot a valve plug, a flow controlling portion at an end of said plug a quench liquid conduit in said plug communicating with a source of quench liquid supply and having an opening at the said end of said plug, an atomizing port in said cylindrical portion having an outer opening at the exterior wall thereof and an inner opening at said conduit whereby said conduit is in free communication with fluid pressure at the inlet side of said orifice when said flow controlling portion is cooperating with said orifice and is cut oil from said pressure when said valve is seated, and means for operating said valve plug.

16. In a valve for controlling fluid flow having a control orifice and a plug cooperating therewith, the combination of a quench fluid conduit in said valve plug having an opening at the end thereof for introducing quench liquid directly to the discharge side of said valve, an atomizing port in said plug connecting said conduit with the inlet side of said valve during at least a portion of the travel of said plug for conducting controlled fluid from the inlet side 01' said valve to said conduit, and means for operating said valve plug.

17. In a fluid pressure control valve having inlet and outlet passages and a control orifice therebetween, the combination with a main valve plug cooperating with said orifice and movable relatively thereto for governing the flow oi fluid through said valve, of a fluid pressure chamber in said control valve having a comparatively restricted fluid connection with said inlet passage and a comparatively unrestricted fluid connecfor cooperating with said orifice to regulate the flow oi 'fiuid therethrough, a cylindrical portion adjacent said flow controlling portion adapted to have a relatively close fit with said orifice to materially reduce the flow of fluid therethrough, a quench liquid conduit in said plug communicating with a source of quench liquid supply and having an opening at the said end of said plug, an atomizing port in said cylindrical portion having an outer openingat the exterior wall of said portion and an inner opening at said conduit whereby the outer opening of said port may be at the inlet side of said orifice when said controlling portion is cooperating therewith and may be at the discharge side of said orifice when said cylindrical portion is cooperating therewith, and means for operating said valve plug.

15. In a valve for controlling fluid flow, the combination with an orifice having a seat, of a valve plug, a flow controlling portion at an end of said plug for cooperating with said orifice and regulating fluid flow therethrough, a cylindrical portion adjacent said flow controlling portion and adapted to cooperate with said orifice to materially reduce the flow of fluid therethrough, a seat on said plug adjacent said cylindrical portion adapted to cooperate with said orifice seat,

tion with said outlet passage, said main valve having a part subjected to pressure in said fluid pressure chamber, a pilot valve having a plug for actuating said main valve plug and for governing the passage of fluid through said unrestricted fluid connection. a stem for operating said pilot plug, means for actuating said stem whereby said unrestricted fluid connection is open when said main valve is open, and means effective when said pilot valve is opened to maintain said pilot valve in open position under varying conditions oi fluid fiow through the main valve orifice.

18. In a fluid pressure control valve having inlet and outlet passages and'a control orifice therebetween, the combination with a main valve plug having a closure portion cooperating with said orifice and movable relatively thereto for governing the flow of fluid through said valve, of'a fluid pressure chamber in said control valve having a comparatively restricted fluid connection with said inlet passage and a comparatively unrestricted fluid connection withsaid outlet passage, said main valve plug having a portion subjected to pressure in said pressure chamber, a pilot valve having a stemnd plug for actuating said main valve plug and for controlling fluid flow through said unrestricted fluid connection, and means for actuating said stem whereby said unrestricted fluid connection is open when said main valve is open, the cross-sectional area of the closure portion of said main valve being greater than the cross-sectional area of the portion subjected to pressure in said chamber to provide a condition of 01! balance in a closing dithe main valve orifice.

EDWARD T. DAHL. 

